In a container, mix the peanut butter, brown sugar, egg, vanilla and baking soda.
Once the mixture is homogeneous, finish by pouring in the chocolate chips. mix one last time. Let stand 10 minutes.
On a baking sheet lined with baking paper, place small balls of cookie dough, the equivalent of two tablespoons for each cookie. Lightly crush the cookies with the back of a spoon to flatten them.
Bake for about 10 minutes until golden brown. Let cool on a rack so that they harden.
Notes
Store for a few days in an airtight box at room temperature.